There are occasions when it is desirable to prevent relative rotation between an outer tube and an inner member coaxial therewith. For example, in a bearing assembly for a downhole fluid powered motor for drilling oil wells, it can be desirable to prevent relative rotation between a stationary bearing sleeve and its surrounding housing. A number of techniques have been tried or might be used for this purpose, but there have been continuing problems due to the severe environment in which such an assembly must operate.
For example, in one embodiment a locking ring has been provided between a housing and a bearing sleeve. The ring was connected in place by four bolts. During service, such bolts can become dislodged, thereby releasing the locking ring and damaging the bearing assembly. Another unacceptable solution is to apply a threaded nut and weld the nut to the housing. This results in obvious difficulties in disassembly. Other arrangements with lock wires, roll pins, and the like are also unsuitable.
It is, therefore, desirable to provide a locking fastener assembly which is secure and not subject to disassembly due to vibration, torque, or moderate wear. The locking fastener assembly should be easily applied and removed when desired.